The invention relates generally to the field of agricultural machinery and, more specifically, to an agricultural machine having apparatus for separating grain from harvested crop.
A combine harvesting machine having a single-cylinder or multi-cylinder threshing mechanism in a rear region is disclosed in EP 0 591 688. The single-cylinder or multi-cylinder threshing mechanism is associated with one or two axial separating rotors, respectively, along a longitudinal direction of the combine harvester. Each of the axial separating rotors has a rotating rotor therein which is provided with entraining elements at its circumference and which, at least in its bottom region, cooperates with a separating grate fixed to the frame and at least partially encasing the rotor. At the top, the rotor is enclosed by enveloping surfaces in such a way that between the rotor, the separating grate and these enveloping surfaces is formed a through-gap through which the agricultural crop is conveyed in spiral paths along the rotor axis by the axial separating rotor. During this conveying process, separation of the grain and straw mixture conveyed by the axial separating rotor occurs, wherein grains, short straw and chaff are separated by the openings formed in the separating grates. In the front region of the axial separating rotor, a considerable proportion of short straw and chaff, so-called impurities, is separated, as the grains which are in the crop stream must first be conveyed by the action of centrifugal force into an outer edge region of the crop stream before they can be separated in the region of the separating grates. To facilitate separation of admixtures, intensive cleaning of the separated crop mixture is required. The cleaning systems are provided for this purpose and mounted behind the axial separating rotor in the agricultural harvesting machine. When there is a considerable proportion of admixtures, the cleaning systems installed on the agricultural harvesting machine are not sufficient to achieve the required purity of crop. As such, the crop must be further cleaned in stationary cleaning devices. This leads to considerable extra expenditure, which greatly increases the costs of the harvesting process.
U.S. Pat. No. 4,869,272 discloses an axial-flow combine harvester having an axial-flow threshing and separating rotor with a rotatable rotor about its longitudinal axis. EP 0 591 688, discloses a rotor having dual functions of threshing and separating the grain from the harvested crop conveyed by the rotor. For this purpose, a front region of the rotor is the threshing zone and an adjoining rear region of the rotor is a separating zone. Both the threshing zone and the separating zone are enveloped at the top by shell surfaces. In the lower region of the rotor, the shell surfaces merge with concaves and separating grates for separating grain from straw mixture. At the beginning of the separating zone, the grains embedded in the crop stream are first moved into an outer region of the spiraling, rotating crop stream before they can pass through the openings of the separating grates. In axial-flow combine harvesters, this leads to a considerably higher proportion of admixtures being separated at the beginning of the separating zone, resulting in overloading the subsequent cleaning components.
The present invention is directed to overcome one or more of the problems as set forth above.
In one aspect of this invention, an agricultural harvesting machine having means for removing and separating grain from the harvested crop such that the harvested crop separated in the separating zones has a reduced proportion of admixtures.
In another aspect of the present invention, there is an agricultural harvesting machine for removing and separating grain from harvested crop, comprising, a threshing zone having threshing members for threshing crop; at least one separating zone having at least one axial separating rotor partially encased by a separating surface and operatively connected to the threshing zone for receiving the threshed crop from the threshing zone and for separating the grain, wherein sections of the separating zone are displaceable in the axial direction of the at least one axial separating rotor; means for separating the grain from the harvested crop; and means for removing the grain from the threshed crop, wherein at least the removal and partial preliminary separation of the grain from the threshed crop take place in the threshing zone.
In yet another aspect of the invention, the separation zone has a separating surface operatively connected to the at least one axial separating rotor, wherein the separating zone has sections which can be displaced in the axial direction of the at least one axial separating rotor to ensure that separation will not begin until a correspondingly large proportion of grains are arranged in an outer region of a rotating crop stream, so that the proportion of admixtures separated by the axial separating rotor remains small.
In still another aspect of the invention, displacement of sections of the separating zone is obtained by encasing the axial separating rotor in a separating surface and by at least partially closing the axial separating rotor with the separating surface.
In yet another aspect of the invention, a particularly advantageous effect of the invention is obtained if the axial separating rotor associated with a tangential threshing mechanism or the separating zone of an axial-flow threshing and separating rotor is constructed in the manner according to the invention.
In another aspect of the invention, the separating surface is segmented and the segments are pivotable to an open and closed position, wherein the separating surface is closed successively beginning in a crop entry region of the separating surface, and opened in the reverse order.
In another aspect of the invention, the separating surface holds, in the circumferential direction of the at least one axial separating rotor, a plurality of pivotable closure flaps. Each of the closure flaps are independently controlled and can close a portion of the separating surface, but in cooperation with closure flaps adjacent to it allows complete covering of the separating surface. In this way, it is ensured that each closure flap need only a small area for pivoting between its opened and closed positions, hence saving space.
In an aspect of the invention, there are closure flaps arranged in an axial direction of the axial separating rotor, so that displacement of sections in a front region of the separating zone is achieved in a structurally simple manner.
In another aspect of the invention, closure flaps are arranged adjacent to each other in a circumferential direction of the axial separating rotor and are pivotably connected to each other by a coupling member, so that a single displacing operation pivots all of the closure flaps that are operatively connected to each other simultaneously.
To simplify displacement of the closure flaps, the closure flaps arranged adjacent to each other in the circumferential direction of the axial separating rotor can be pivotably connected to each other by a coupling member, so that a single displacing operation pivots all the closure flaps connected to each other simultaneously.
In still another aspect of the invention, the closure flaps are opened and closed such that the closure flaps are arranged one behind the other and operatively and pivotably connected to each other by a common pivot mechanism.
In yet another aspect of the invention, there are closure flaps that are successively opened and closed by coupling members. The closure flaps move along slot guides that have curved paths, wherein the shape of the curved paths ensures that closing of the closure flaps begins at the beginning of the axial separating rotor and opening of the closure flaps begins with the closure flaps closest to the rotor end. The axial displacement is effected by displacement means known in the art, which are operatively connected to the slot guides by at least one coupling rod.
An aspect of the invention is slot guides pivotably arranged about a shaft pointing in the axial direction of the at least one axial separating rotor, wherein the shape of the slot guides ensure the order of opening and closing of the closure flaps. The arrangement of the slot guides can lead to a considerable reduction of displacement paths hence a space savings.
In another aspect of the invention, closure flaps are the displacement means, and the closure flaps are independent of each other and actuated independently of each other to achieve flexible displacement capacities.
In still another aspect of the invention, the agricultural machine has a plurality of axial separating rotors, displacement means and associated displacement mechanisms, wherein the displacement mechanism is arranged in a gap between the axial separating rotors to reduce the particles swirling around said gap.
In yet another aspect of the invention, the crop passing through the separating surface is not hindered in its movement by the closure flaps. Further, adjacent closure flaps can have such a pivot range that when in their opened position, they form the shape of a funnel opening in a radial direction.
In another aspect of the invention, displacement of sections in a front region of the separating zone facilitates separation of admixtures and depends on crop properties such as moisture, fracture behaviour, grain size. The displacement varies as a function of the separation of admixtures in the front region of the separating zone.
An aspect of the invention is achieved by displacing sections in a front region of the separating zone, wherein displacement is effected automatically as a function of the separation of admixtures. Sensors sense the proportion of admixtures, and a control and evaluation unit receive the sensed signal and use said signal to control the through flow of admixtures and to correct the through flow via opening or closing closure flaps.
The above aspects are merely illustrative and should not be construed as all-inclusive and limiting to the scope of the invention. The aspects and advantages of the present invention will become apparent, as it becomes better understood from the following detailed description when taken in conjunction with the accompanying drawings.